Method of making cord tips



March 19, 1929. w v, THOMPSON 1,706,0Q5

METHOD OF MAKING CORD TIPS Filed Jan. 26, 1922 Patented Mar. 19, 1929.

UNITED STATES PATENT OFFICE.

WALTER V. THOMPSON, 0F ROSELLE PARK, NEW JERSEY, ASSIGNOR TO WESTERN ELECTRIC COMPANY, INCORPORATED, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

METHOD OF MAKING CORD TIPS.

Applicationfiled January 26, 1922. Serial No. 531,842.

This invention relates to electrical connectors and a method for applying said connectors to insulated wires to form terminals thereon.

The object of the invention is to provide a connector for electrical wires which may be securely attached without scraping the insulation from the wires and without the use of solder to secure it to the conductor.

The invention provides a connector having spike members which may be pressed through the insulation of a conductor thereby making contact with the metal strands therein and a body portion which may be simultaneously bent or wrapped about the insulated conductor for securely attaching the cord tip thereon.

In making electrical connections in large numbers as is done, for example, in telephone exchanges, it is important to provide connectors or cord tips which will insure a perfect connection and which will give lasting service. It has heretofore been the practice to cut the insulated conductor wire to the proper length, to cut or scrape the insulation from the end of the conductor, to wrap strands of thin wire about the end'of the conductor, to solder thereto the conducting portion of the connector and to bend the body portion of the connector about the end of the insulated wire to securely fasten the same thereto.' This process is not only tedious, but expensive owing to the numerous operations involved. The present invention provides a connector and a. method of attaching it to an insulated conductor which performs substantially simultaneously the steps of securing the connector to the conductor, making an electrical connection between the cord tip and the conductor and cutting the conduct-or to the proper length.

In the drawings, disclosed Fig. 1 is an enlarged view of a connector which embodies the invention in its preferred form. Fig. 2

' shows the improved connector attached to an insulated conductor. Fig. 3 is an enlarged cross sectional View showing the projections of the connector piercing the insulation and contacting with the stranded conductors therein. Fig. 4 is a partial end elevation of a punch press which may be used for performing the steps of my improved method. Fig.

the apparatus with the invention comprises a metal punching which is provided with a connecting arm 1 having a U -shaped contacting tip 2. A body or shank portion 3 of the improved connector is provided with ears or wings 4 on either side thereof which may be crimped or bent around the insulated wire to which the connector is to beapplied. Two sides of triangularly shaped holes are cut in the shank portion 3 and the cut portions punched through to form sharp pointed projections 5 of metal which project at right angles to the surface of the shank.

Fig. 2 shows the improved connector applied to an insulated wire which comprises a series of strands 6, an insulating coating of rubber 7 and a braided wrapping of fibrous material 8. In applying the connector to the conductor, the projections 5 are forced through the braided wrapping 8 and the insulating coating of rubber 7 into the stranded conductor wires 6 (Fig. 3), the ears or wings 4 of the shank portion being crimped or wrapped around the outside of the conductor to secure the connector to the conductor and to hold the projections 5 in engagement with the stranded conductors 6. The conductor is then cut at that end of the body or shank por tion 3 adjacent the connecting arm 1, to leave the arm entirely exposed as is shown in Fig. 2.

Figs. 4 and 5 illustrate an apparatus which may be employed to perform my improved method of attaching to insulated conductors a connector made in accordance with my invention, which method consists in forcing projections on the connector through the insulation of the conductor thereby establishing electrical connection between the strands within the conductor and the connector, crimping the body portion of the connector on the conductor to hold the connector thereon and cutting the conductor to the proper length so as to expose the contactingarm of the connector: The illustrated means for performing these operations consists of a punch press provided with a grooved stationary die 9 into which the conductor and connector are pIaced, a cylindrical lug or stop 10 being provided for determining the position of the connector and the conductor on the stationary die 9. A reciprocating die 11 cooperating with die 9 is provided with a V-shaped groove 12 which registers with groove 13 in stationary die 9 so that, in its downward movement the sides of the groovedreciprocating die engage the upturned wings 4 of the connector seated in groove 13 of stationary die 9, and crimps them around the insulated conductor. Reciprocating die 11 is also provided with a chisel blade 14: having a knife edge 15 which in its downward movement cuts the insulated conductor to the proper length exposing the contacting arm 1 of the connector.

From the above, it will be seen that the piercing,crimpingandcuttingoperationsmay be accomplished substantially simultaneously. The means for doing this however is not to be understood as being limited to that shown in the disclosure which merely illustrates one apparatus with which the improved method may be performed.

lVhat is claimed is:

The method of making a cord tip for telephone cords which consists in laying an insulated conductor in a channel formed in a sheet metal blank having a projecting terminal,

substantially simultaneously forcing the sidesof the channel around said insulated conduct-or to form a jacket to hold it firmly, cutting the insulated conductor where it emerges from the jacket, and making a permanent electrical connection between said conductor and tip by forcing sharp projections on the jacket through the insulation and into contact with the conductor.

In Witness whereof, I hereunto subscribe my name this 24th day of January A. D., 1922.

l/VALTER V. THOMPSON. 

